[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 230603
SWODY1
SPC AC 230602

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0102 AM CDT FRI JUN 23 2006

VALID 231200Z - 241200Z

...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS NEW ENGLAND TO LOWER
MS VALLEY...

...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS CENTRAL/NRN GREAT
PLAINS...

...SYNOPSIS...
SUBTLE PATTERN SHIFT IS ANTICIPATED THROUGH PERIOD...AS HEIGHTS
GRADUALLY RISE ACROSS GREAT BASIN AND DIFFUSE TROUGHING DEVELOPS
FROM OH VALLEY ACROSS SERN CONUS...S OF PERSISTENT HUDSON BAY
VORTEX.  SEVERAL MINOR MIDDLE-UPPER LEVEL PERTURBATIONS ARE EXPECTED
IN NWLY/WLY FLOW OVER CENTRAL/ERN CONUS...SOME OF WHICH WILL BE
CONVECTIVELY DEVELOPED/ENHANCED AS MCV FEATURES.  SHORTWAVE TROUGH
-- NOW EVIDENT IN MOISTURE CHANNEL IMAGERY OVER WRN WA AND SWRN BC
-- APPEARS TO BE POORLY RESOLVED BY MOST 23/00Z OPERATIONAL MODELS
AND EVEN MOST 22/21Z SREFX MEMBERS...EXCEPT PERHAPS FOR OPERATIONAL
SPECTRAL.  THIS FEATURE SHOULD MOVE THROUGH MEAN RIDGE AND REACH
N-CENTRAL PLAINS AROUND 24/00Z.

AT SFC...BAROCLINIC ZONE HAS BEEN DIFFUSED GREATLY BY NUMEROUS
OUTFLOW BOUNDARIES...BUT GENERALLY EXTENDS FROM NY SWWD ALONG OH
VALLEY TO SRN HIGH PLAINS.

...NEW ENGLAND TO LOWER MS VALLEY...
UP TO 2-3 CLUSTERS OR BANDS OF TSTMS ARE POSSIBLE WITHIN THIS
AREA...MOVING GENERALLY EWD...MAIN THREAT BEING DAMAGING WIND. 
MARGINALLY SVR HAIL ALSO IS LIKELY...WITH LINEAR AND MULTICELLULAR
MODES PREDOMINANT.  CONSIDERABLE UNCERTAINTY REMAINS ABOUT LOCATION
OF MOST CONCENTRATED THREAT...GIVEN PRESENCE OF ABUNDANT CONVECTION
AND OUTFLOW AIR OVER REGION ATTM.  THEREFORE HIGHEST PROBABILITIES
MAY BE COMPRESSED/DIVIDED OR SHIFTED IN SUCCEEDING OUTLOOKS.  PRIND
MOST SVR ACTIVITY SHOULD EVOLVE...
1. FROM AFTERNOON DEVELOPMENT ALONG OUTFLOW-REINFORCED BAROCLINIC
ZONE...AND/OR
2. ALONG/AHEAD OF REMNANTS OF MORNING MCS...AIDED BY ASSOCIATED
CONVERGENCE...DIFFERENTIAL HEATING ZONES...AND MESOSCALE SHEAR/UVV
ENHANCEMENTS PROVIDED BY MCVS.

SVR THREAT SHOULD DIMINISH AFTER DARK AS PROSPECTIVE INFLOW LAYERS
ARE STABILIZED BY COMBINATION OF SFC DIABATIC COOLING...OUTFLOW
AIR...AND NEAR COAST...RELATIVELY COLD SEA BREEZE.

...CENTRAL/NRN GREAT PLAINS...
TSTMS ARE FCST TO DEVELOP AND INCREASE IN COVERAGE DURING MID/LATE
AFTERNOON.  ACTIVITY SHOULD FORM INITIALLY IN HIGHER TERRAIN OF
BLACK HILLS SWD TOWARD NERN CO...AND DEVELOP/SPREAD SEWD AMIDST
INCREASING LARGE SCALE ASCENT AHEAD OF MID/UPPER LEVEL TROUGH NOW
OVER PACIFIC NW.  WHEN COMBINED WITH NWLY MIDLEVEL FLOW...SELY SFC
WINDS EMANATING FROM POSTFRONTAL AIR MASS WILL YIELD FAVORABLE LOW
LEVEL HODOGRAPHS AND DEEP-LAYER SHEAR FOR SUPERCELLS...ESPECIALLY
FROM SWRN/S-CENTRAL SD SWD THROUGH WRN NEB.  MOISTURE WILL BE
LIMITED GIVEN POSTFRONTAL ORIGIN OF INFLOW-LAYER TRAJECTORIES...WITH
SFC DEW POINTS REMAINING GENERALLY IN 50S F.  HOWEVER...BENEATH
MIDLEVEL LAPSE RATES NEAR 9 DEG C/KM...THIS SHOULD SUFFICE TO YIELD
AFTERNOON MLCAPES 2000-3000 J/KG OVER MUCH OF OUTLOOK AREA. 
COMBINED CAPE/SHEAR PROFILES INDICATE POTENTIAL FOR VERY
LARGE/DAMAGING HAIL FROM SOME TSTMS BEFORE ACTIVITY EVOLVES INTO ONE
OR TWO SEWD-MOVING...NOCTURNAL MCS WITH DAMAGING WIND MAIN THREAT. 
STRONGLY MIXED SUBCLOUD LAYER SHOULD ALSO CONTRIBUTE TO DIURNAL WIND
DAMAGE POTENTIAL.

...SRN PLAINS TO LOWER MS VALLEY...
SCATTERED TO WIDELY SCATTERED TSTMS IN CLUSTERS ARE EXPECTED INVOF
LOOSELY DEFINED FRONTAL ZONE...FROM LOWER MS VALLEY WSWWD ACROSS
ARKLATEX...N AND W TX...ERN NM...AND PORTIONS TX/OK PANHANDLES. 
SOME OF THIS ACTIVITY WILL OCCUR IN ENVIRONMENTS OF FAVORABLE
BUOYANCY -- I.E. MLCAPES 1500-3000 J/KG -- AND MAY BRIEFLY PRODUCE
SVR HAIL/GUSTS.  EFFECTIVE FRONTAL ZONE OVER THIS REGION IS YET TO
TAKE SHAPE AND WILL BE STRONGLY MODIFIED/MODULATED BY POSITION AND
STRENGTH OF OUTFLOW AIR MASSES LEFT BEHIND BY PRIOR
OVERNIGHT/MORNING ACTIVITY.  ALTHOUGH A FEW COLD POOL DRIVEN
MULTICELL CLUSTERS MAY CONCENTRATE SVR REPORTS WITHIN THIS BROAD
ARC...MESOSCALE UNCERTAINTIES AND LACK OF MORE ROBUST KINEMATIC
SUPPORT PRECLUDE MORE THAN MRGL SVR PROBABILITIES ATTM.  VERTICAL
WIND AND SHEAR PROFILES ARE FCST TO BE QUITE WEAK ACROSS MOST OF
THIS AREA...INDICATING LIMITED POTENTIAL FOR ORGANIZED SVR EVENT.

..EDWARDS/TAYLOR.. 06/23/2006